As is known, a good many electronic circuit designs involve the provision of a voltage threshold detector, for instance to detect such drops in the supply voltage as may imply malfunction of the circuit.
Consider in particular non-volatile storage circuits integrated into a semiconductor, wherewith a drop in the supply voltage while the programming voltage is present may impair the memory erasing and programming steps.
A known type of detector circuit is disclosed in U.S. Pat. No. 4,975,883, for example.
Further, the reference voltages against which the comparison is performed, are obtained, for example, from resistive dividers of a supply voltage. Such reference voltages are not, therefore, constant as temperature, and even the supply voltage, vary.
The technical problem underlying this invention is to provide a circuit solution that allows a peculiarly low threshold voltage to be detected, and accordingly, the drawbacks with which the prior approaches are beset to be overcome.